Bearing-like structure to control deflections of a rotating component

ABSTRACT

A bearing like surface on a stationary component reduces deflection of an adjacent rotating component. The stationary component is generally parallel to and offset from a rotational component. The rotational component rotates about a central axis. Protrusions located on the stationary component are in contact with the rotational component to prevent deflection of the rotational component while reducing the friction between the rotational and stationary component. The protrusions have a generally flat surface that may be used to affix the protrusions to the stationary component. An arced surface of the protrusions is in contact with the rotating component. The number, size and the shape of the protrusions are determined by the requirements of the application.

BACKGROUND OF THE INVENTION

The present invention is a bearing-like structure on a stationarycomponent that reduces deflections on an adjacent rotating component.More particularly, protrusions located on the stationary componentcontact the rotational component to prevent deflection of the rotationalcomponent while reducing the friction between the rotational andstationary components.

Rotating components are utilized in many devices, such as fan blades ina turbine engine. Deflections may occur at the outer portions of thecomponent as the component rotates about an axis. At higher speeds andafter long periods, greater amounts of deflection can occur. There areseveral ways to prevent the rotating component from deflecting. Forexample, the rotating component can be made thicker or stronger towithstand the forces causing deflection. However, this solution addsweight, may increase size of the component, and is not feasible in allapplications.

An alternate method of controlling deflections is placing a stationarycomponent adjacent to the rotating component to provide support for theouter portions of the rotating component to prevent deflection. As therotating component rotates about the axis, friction builds between therotating component and the stationary component at points of contact.The friction increases as the speed of the rotational componentincreases. Heat is also a result of the friction between the rotationalcomponent and the stationary component.

Thus, an arrangement that provides support to a rotating component whilereducing friction between the rotating component and a stationarycomponent is needed.

SUMMARY OF THE INVENTION

The present invention provides a bearing-like surface on a stationarycomponent to reduce deflections on an adjacent rotating component. Thearrangement is preferably used in a turbine engine between a fan bladeand housing.

The stationary component extends generally parallel to, and offset from,a rotational component. The rotational component rotates about a centralaxis. In order to prevent deflection, protrusions located on thestationary component are in contact with the rotational component. Theprotrusions reduce an amount of surface area in contact between therotational component and the stationary component, lowering the amountof friction created. Additionally, the protrusions may be coated in, orformed from, a material to providing a lower friction surface forcontact. The protrusions may be affixed to the stationary component orformed as one-piece with the stationary component.

For example, in a tip turbine engine, the fan blades are in contact witha stationary component that is part of the engine housing or case. Thestationary component supports the outer ends of the fan blades to limitdeflection of the fan blades during rotation. In the preferredembodiment, the stationary component is affixed to the turbine exhaustcase housing and the fan blades rotate about the centerline of theturbine engine. Protrusions are located on the stationary component toreduce the friction between the stationary component and the fan blades.

In alternate embodiments for a tip turbine engine, the stationarycomponent could be the fan exhaust case housing, the fan inlet housingor the housing for the combustor assembly. In other gas turbine engines,the rotating module can be a fan, compressor or turbine rotor segment incontact with an adjacent or accommodating stationary components, orcombustor and diffuser case or housings.

The protrusions have a generally flat surface in contact with thestationary component. The flat surface may be used to affix theprotrusions to the stationary component. An arced surface of theprotrusions is in contact with the rotating component. The number, sizeand the shape of the protrusions are determined by the requirements ofthe application.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of this invention will becomeapparent to those skilled in the art from the following detaileddescription of the currently preferred embodiment. The drawings thataccompany the detailed description can be briefly described as follows:

FIG. 1 is a general view a tip turbine engine;

FIG. 2 is an internal view of the tip turbine engine;

FIG. 3 is an enlarged view of a portion of a tip turbine engine fromarea E of FIG. 2;

FIG. 4 is a side view of one embodiment of the present invention; and

FIG. 5 is a schematic showing the locations of protrusions along astationary component in one embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a general perspective partial sectional view of a tipturbine engine type gas turbine engine 10. The engine 10 includes anouter nacelle 12, a rotationally fixed static outer support structure 14and a rotationally fixed static inner support structure 16. A multitudeof fan inlet guide vanes 18 are mounted between the static outer supportstructure 14 and the static inner support structure 16. A nose cone 20is preferably located along the engine centerline A to smoothly directairflow into an axial compressor 22 adjacent thereto. The axialcompressor 22 is mounted about the engine centerline A behind the nosecone 20.

A fan-turbine rotor assembly 24 is mounted for rotation about the enginecenterline A aft of the axial compressor 22. The fan-turbine rotorassembly 24 includes a multitude of hollow fan blades 28 to provideinternal, centrifugal compression of compressed airflow from the axialcompressor 22 for distribution to an annular combustor 30 located withinthe rotationally fixed static outer support structure 14.

A turbine 32 includes a multitude of tip turbine blades 34 whichrotatably drive the hollow fan blades 28 relative to a multitude of tipturbine stators 36 which extend radially inwardly from the static outersupport structure 14. The annular combustor 30 is axially forward of theturbine 32 and communicates with the turbine 32.

Referring to FIG. 2, in operation, air enters the axial compressor 22,where it is compressed by compressor blades 52 and compressor vanes 54.Each fan blade 28 includes an inducer section 66, a hollow fan bladesection 72 and a diffuser section 74. The inducer section 66 receivesairflow from the axial compressor 22 generally parallel to the enginecenterline A and turns the airflow from an axial airflow directiontoward a radial airflow direction. The airflow is radially communicatedthrough a core airflow passage 80 within the fan blade section 72 wherethe airflow is centrifugally compressed. From the core airflow passage80, the airflow is turned and diffused toward an axial airflow directiontoward the annular combustor 30. The airflow is further compressedcentrifugally in the hollow fan blades 28 by rotation of the hollow fanblades 28. From the core airflow passage 80, the airflow is turned anddiffused axially forward in the engine 10 into the annular combustor 30.The compressed core airflow from the hollow fan blades 28 is mixed withfuel in the annular combustor 30 and ignited to form a high-energy gasstream. The high-energy gas stream is expanded over the multitude of tipturbine blades 34 mounted about the outer periphery of the fan-turbinerotor assembly 24 to drive the fan-turbine rotor assembly 24, which inturn drives the axial compressor 22 through the gearbox assembly 90.Concurrent therewith, the fan-turbine rotor assembly 24 discharges fanbypass air axially aft to merge with the core airflow from the turbine32 in an exhaust case 106. A multitude of exit guide vanes 108 arelocated between the static outer support housing 44 and the rotationallyfixed static outer support structure 14 to guide the combined airflowout of the engine 10 to provide forward thrust. An exhaust mixer 110mixes the airflow from the turbine blades 34 with the bypass airflowthrough the fan blades 28.

FIG. 3 illustrates an enlarged portion of the fan blades 28 and theturbine 32. The diffuser section 74 of the fan blades 28 is in contactwith a stationary component 120 that is part of the turbine 32 housing.The stationary component 120 sustains the outer ends of the fan blades28 at the diffuser section 74 to limit deflection of the fan blades 28during rotation. The stationary component 120 is affixed to the turbine32 housing and the fan blades 28 rotate about the centerline A (shown inFIG. 1) of the turbine engine 10. In order to prevent deflection thestationary component 120 is in contact with the diffuser section 74 ofthe fan blades 28 over the complete rotation of the fan blades 28. Asthe fan blades 28 rotate friction occurs between the stationarycomponent 120 and the diffuser section of the fan blades 28. Protrusions122 are located on the stationary component 120 to reduce the contactarea between the stationary component 120 and the fan blades 28. Theprotrusions 122 are in contact with the fan blades 28. However, due tothe protrusions 122, the fan blades 28 do not contact the larger surface124 of the stationary component 120 during rotation. The reduction insurface area of the contact between the fan blades 28 and the stationarycomponent 120 lowers the amount of friction created. Additionally, theprotrusions 122 may be coated in, or formed from, a material to providea lower friction surface for contact. Although the protrusions are shownare affixed to the stationary component 120 the protrusions 122 may alsobe formed as one-piece with the stationary component 120.

Although the above embodiment discloses one example of a turbine engineany device having a rotating component and a stationary component may bebenefit from the present invention. Referring to FIG. 4 a stationarycomponent 130 is generally parallel to and offset from a rotationalcomponent 132. The rotational component 132 rotates about a central axisB. Protrusions 134 located on the stationary component 130 may be incontact with the rotating component 132 or slightly spaced, as shown. Itis not required that the rotating component 132 be in contact with theprotrusions 134 at all times. For example, contact between theprotrusions 134 and the rotating component 132 might occur when therotating component 132 begins to deflect. As an example, when therotating components 132 begin to deflect at higher speeds, it may takeup a prior clearance and contact protrusions 134. The protrusions 134would then contact with the rotating component 132 to limit any furtheramount of deflection. Once the deflections returns to normal therotating component 132 would no longer be contacting the protrusions134.

In the embodiment shown there are four protrusions 132 located on thestationary component 130. The protrusions 134 have a generally flatsurface 136 in contact with the stationary component 130. The flatsurface 136 may be used to affix the protrusions 134 to the stationarycomponent 130. An arcuate surface 138 of the protrusions 134 willcontact with the rotating component 132, as shown. The number, size ofthe protrusions 134, including the height, and the shape of theprotrusions 134 are determined by the requirements of the application.One skilled in the art would know the proper number, size and shape ofthe protrusions.

FIG. 5 illustrates the embodiment having four protrusions. Theprotrusions 134 are spaced concentric about the center axis B of therotating component 132. The protrusions 134 are evenly spaced from oneanother to maintain symmetric loading on the rotating component 132 whenit is in contact with the protrusions 134.

Although a preferred embodiment of this invention has been disclosed, aworker of ordinary skill in this art would recognize that certainmodifications would come within the scope of this invention. For thatreason, the following claims should be studied to determine the truescope and content of this invention.

1. A turbine engine comprising: a fan having a rotating component thataxially deflects; and a stationary component having a portion facing andadjacent to said rotating component wherein at least two protrusionsextend from said portion toward said rotating component to limit axialdeflection of said fan.
 2. The turbine engine of claim 1, wherein saidat least one protrusion is a plurality of protrusions.
 3. The turbineengine of claim 2, wherein said plurality of protrusions are spacedconcentric about a center of said rotating component.
 4. The turbineengine of claim 2, wherein said plurality of protrusions are evenlyspaced from one another.
 5. The turbine engine of claim 1, wherein saidat least one protrusion is in contact with said rotating component. 6.The turbine engine of claim 5, wherein said at least one protrusion hasan arced surface contacting said rotating component and a generally flatsurface contacting said stationary component.
 7. The turbine engine ofclaim 1, wherein said rotating component is a fan blade and saidstationary component is a fan housing.
 8. The turbine engine of claim 1,wherein said at least one protrusion and said stationary component areformed as one-piece.
 9. The turbine engine of claim 1, wherein said atleast one protrusion is coated to provide a lower friction surface. 10.The turbine engine of claim 1, wherein said at least one protrusion isinitially spaced from said rotating component.
 11. A turbine enginecomprising: a fan having at least one fan blade rotating about a centralaxis; a stationary component having a portion facing and adjacent tosaid at least one fan blade; and a plurality of protrusions extendingfrom said stationary component toward said at least one fan blade tolimit axial deflection of said fan, wherein said plurality ofprotrusions are spaced concentrically about said central axis.
 12. Theturbine engine of claim 11, wherein said plurality of protrusions areeach in contact with said at least one fan blade.
 13. The turbine engineof claim 12, wherein said plurality of protrusions have an arced surfacecontacting said at least one fan blade and a generally flat surfacecontacting said stationary component.
 14. The turbine engine of claim11, wherein said plurality of protrusions and said stationary componentare formed as one-piece.
 15. The turbine engine of claim 11, whereineach of said plurality of protrusions are coated to provide a lowerfriction surface.
 16. The turbine engine of claim 11, wherein saidplurality of protrusions are initially spaced from said rotatingcomponent.
 17. A device comprising: a rotating compressor componentdefining a central axis about which said component rotates; a stationarycomponent having a portion facing and adjacent to said rotatingcomponent; and a plurality of protrusions extending from said stationarycomponent portion and said rotating compressor component and towards theother to limit axial deflection of said rotating compressor component,wherein said plurality of protrusions are spaced concentric about saidcentral axis.
 18. The device of claim 17, wherein said plurality ofprotrusions are forward on said stationary component.
 19. The device ofclaim 17, wherein said plurality of protrusions do not contact the otherof said stationary component and said rotating component, wherein saidrotating component rotates at low speeds.
 20. The device of claim 17,wherein said at least one protrusion has an arced surface.
 21. Theturbine engine of claim 1, wherein the rotating component is a fanblade.
 22. The turbine engine of claim 1, wherein the protrusion extendsaxially forward from the portion.
 23. The turbine engine of claim 1,further comprising an axial compressor axially forward of the fan blade.24. The turbine engine of claim 1, wherein the fan blade is a hollow fanblade having an inducer section, a hollow fan blade section, and adiffuser section, wherein the rotating component is disposed in thediffuser section.
 25. The turbine engine of claim 24, wherein theairflow from the axial compressor is turned radially outwards in theinducer section, wherein airflow is turned axially forward in thediffuser section.
 26. The turbine engine of claim 24, wherein acombustor section and turbine section are radially outward of the fanblade.
 27. The turbine engine of claim 1, wherein the rotating componenthas an axially rearward face adjacent and opposing an axially forwardface of the at least one protrusion.
 28. The turbine engine of claim 1,wherein the plurality of protrusions is arranged to contact an axialface of the rotating component.
 29. The turbine engine of claim 11,wherein the plurality of protrusions extend from said portion towardsaid rotating component to limit axial deflection of said fan.
 30. Thedevice of claim 17, wherein the plurality of protrusions extend fromsaid portion toward said rotating component to limit axial deflection ofsaid fan.